chore: remove legacy .gitignore, only keep HarmonyOS project files

.gitignore

@@ -1,79 +0,0 @@
-# Python
-__pycache__/
-*.py[cod]
-*$py.class
-*.so
-.Python
-develop-eggs/
-dist/
-downloads/
-eggs/
-.lib/
-lib64/
-parts/
-sdist/
-var/
-wheels/
-*.egg-info/
-.installed.cfg
-*.egg
-
-# Virtual Environment
-venv/
-test_venv/
-ENV/
-env/
-
-# IDE
-.vscode/
-.idea/
-.arts/
-.codeartsdoer/
-*.swp
-*.swo
-*~
-
-# Database
-*.db
-*.sqlite
-*.sqlite3
-
-# Logs
-*.log
-logs/
-
-# OS
-.DS_Store
-Thumbs.db
-
-# Sensitive
-.env
-*.key
-*.pem
-config.json
-
-# Build
-dist/
-
-# Temporary
-*.tmp
-*.bak
-
-# AI Generated
-jimeng*.png
-
-# Test Cache
-.pytest_cache/
-
-# Web config (contains passwords, secret keys)
-web_config.json
-
-# Node.js
-node_modules/
-
-# Test artifacts
-/session_*/
-task_archive/
-ts/
-build/trulymem/
-harmonyos/.hvigor/